But here, obviously, you’re referring to some plugin.
Without knowing what plugin you’re using, it’s almost impossible to answer your question.

Some of them are here: https://www.ads-software.com/plugins/tags/image-map/

Pro tip: Open your list of installed plugins. When you find the imagemapping one, click on “view details” to get a modal window with plugin page. There, you may find useful sections, like “Installation”, “FAQ” and/or may be able to jump directly to the support forum for this particular plugin!
Once you find out which image mapping plugin you’re using, have a read at the